The present invention relates to a multi-piece solid golf ball of three or more layers which is composed of a solid core, an intermediate layer and a cover, and is endowed with excellent properties such as flight performance, feel on impact, controllability, and scuff resistance.
In recent years, the number of layers in solid golf balls has been increased from the conventional two-piece ball construction composed of a solid core and a cover by additionally providing an intermediate layer between the solid core and the cover, and efforts are being made to optimize each of the layers. Various three-piece golf balls have been disclosed in which a good flight performance and an excellent durability, feel and controllability are achieved by giving the core itself an optimized hardness profile and by providing the ball as a whole—including the core, the intermediate layer and the cover—with an optimized hardness profile.
For example, JP No. 3505922 (and the corresponding specification of U.S. Pat. No. 5,830,085) discloses a three-piece solid golf ball having a core, an intermediate layer and a cover, which ball satisfies the following relationship: core center hardness<core surface hardness<intermediate layer hardness<cover hardness. However, this golf ball has a low rebound.
JP-A 2004-49913 (and the corresponding specification of U.S. Pat. No. 6,663,507) discloses a multi-piece solid golf ball which has, between a core and a cover, an intermediate layer composed primarily of a binary copolymer and having a Shore D hardness of at least 50. However, the flight performance and scuff resistance of this golf ball leave something to be desired.
U.S. Pat. Nos. 6,409,614, 6,277,035, 6,991,562 and 7,160,211 disclose multi-piece solid golf balls having a core, a soft inner cover and a hard outer cover, which outer cover is a cover having a high Shore D hardness. However, these golf balls do not have both a satisfactory controllability and a satisfactory feel. Hence, there has remained room for improvement.
In the golf ball of U.S. Pat. No. 6,561,928, the total thickness of the cover encasing the core is too large, resulting in a decrease in flight performance.
Because the many multi-piece solid golf balls which have been disclosed to date fail to satisfy all the desired attributes—namely, flight performance, feel on impact, controllability/spin performance, scuff resistance and durability, a need has been felt for further improvement.